Ecological Systems and Devices Annotation << Back PECULIARITIES OF WAVE PROCESSES IN THE AREA OF CAPE OSTRY, THE SOUTHEASTERN COAST OF THE SAKHALIN ISLAND D.P. Kovalev, P.D. Kovalev The time series of sea level fluctuations with a one second discreteness were obtained using five autonomous wave meters ARW – 10 installed at different distances from the shore in the water area in the area of Cape Ostry, south-east coast of Sakhalin Island. The study of the wave field with a focus on the range of swell waves and infragravity (IG) waves has been carried out. Calculation of the seiches was shown that in the studied water area there are no conditions for the excitation of seiches with periods of peaks detected in the spectra. Wave processes in the range of periods of sea level fluctuations from 15 minutes to 3.5 hours, as shown by the model calculation, are shelf seiches. In the range of IG waves from 30 s to 10 min, well-pronounced wave processes were detected, the coherence between which for different pairs of devices exceeds the confidence level, and the growth of the phase with a decrease in the oscillation period indicates on the cross-shore direction of waves propagation. The peculiarity of the change in the energy of the detected wave processes is noted, which consists in changing the ratio of the oscillation energy for different devices and periods. A model study of the longshore structure of edge waves using of Ursell dispersion relation has been carried out. It is shown that for the detected peaks in the spectral density for the range of 30 s – 10 min of all devices, the existence of zero-mode edge waves is possible, which may be responsible for the formation of rhythmic relief forms in the coastal zone south of Cape Ostry. The explanation of the observed feature of the change in the energy ratios of spectral dencity peaks is given with using the cross-shore profile of refl ected waves incident normally on the shore of the IG waves, which is approximately described by the Bessel function of the first kind of zero order. The profile of such waves signifi cantly depends on their period and the transverse dimensions are significantly smaller than for edge waves. It is shown that the spectral density of sea level fluctuations in the range of wind waves and swells are sufficiently smoothed and do not contain significantly pronounced energy rises. Keywords: swell, infragravity waves, seiches, edge waves. DOI: 10.25791/esip.10.2023.1401 Pp. 03-14.